Hillary Clinton wants more time through the end of the year to think about whether she'll run for president in 2016, the former secretary of state told ABC's Diane Sawyer in an exclusive interview in advance of Tuesday's release of her new memoir, "Hard Choices."

"I will be on the way to making a decision by the end of the year, yes," she told Sawyer.

But first, Clinton said, she'll go on a book-signing tour beginning this week and she plans to campaign for Democratic candidates running in 2014.

"Certainly not before then," Clinton said, referring to the end of 2014. "I just want to kind of get through this year, travel around the country, sign books, help in the midterm elections in the fall, and then take a deep breath and kind of go through my pluses and minuses about what I will – and will not – be thinking about as I make the decision."

The full interview with Hillary Clinton and ABC's Diane Sawyer will air during a one-hour ABC News prime time special on Monday, June 9, at 9 p.m. ET. ABC's Robin Roberts will follow up with Clinton's first live interview, on Tuesday, June 10, on "Good Morning America."

Clinton said it is "probably likely" that she will not make an announcement until next year.

"I'm not positive about that, but I think, you know, the way I make decisions, that's probably likely," Clinton said.

Until Clinton makes an announcement, she remains the Democratic Party's leading option for the White House in 2016 – a dynamic that could discourage some would-be contenders from laying the groundwork for a 2016 bid.

Clinton also fares well in public perceptions in the new poll: 67 percent of Americans view her as a strong leader, 60 percent say she's honest and trustworthy, and 59 percent say she has new ideas for the country's future.

But in the ABC News interview Clinton dismissed the notion that her deliberations are hurting the party or affecting other potential candidates.

"People can do whatever they choose to do on whatever timetable they decide," she said, noting that her husband, Bill Clinton, didn't begin his first presidential campaign until the fall before his election year.

"Bill Clinton started running for president officially in, like September or October of 1991. So, no, I just don't think that' a real concern. People will do what they think is best for them," Clinton said. "Whether they choose to seek the presidency or not is very personal, for everybody."

Will Clinton Testify On Benghazi?

In the interview, Sawyer also asked about the new congressional committee that will examine the Sept. 11, 2012 attack on the U.S. diplomatic facility in Benghazi, Libya. Clinton did not say definitively whether or not she will testify before the new committee if called to do so.

"That's going to be up to the people running the hearing," she said. "We'll see what they decide to do, how they conduct themselves, whether or not this is, you know, one more travesty about the loss of four Americans, or whether this is, in the best tradition of the Congress, an effort to figure out how – what we can do better."

In the new ABC News-Washington Post poll, 59 percent of Americans approve of Clinton's job performance as Secretary of State, but that declines to 37 percent on her handling of the attack in Benghazi, where a U.S. diplomat and three other Americans were killed.

Since the Benghazi attack, Congressional Republicans have asserted the Obama administration – and, specifically, the State Department under Clinton's leadership – mishandled the crisis as it unfolded and misled the American public afterward. Administration officials, including Clinton, have denied those Republican-led charges, accusing the GOP of politicizing the attack.

Last month, House Speaker John Boehner, R-Ohio, announced the formation of a new special committee to investigate the attack. House Democrats reluctantly participated, naming their own members to the committee.